As a result, with less than three weeks before the deadline to obtain health insurance, some people who think they have successfully enrolled in a plan may find themselves without coverage, insurance officials say.

"The enrollment information is improving. [But] there are still significant steps to be made to continue to improve it," said Scott Keefer, vice president of policy and legislative affairs for Blue Cross and Blue Shield of Minnesota. "The bottom line is that we have some time, but there is urgency to make sure people can get their cards and get health services by Jan. 1.

"We are in a very, very delicate phase where we seriously run the risk of people showing up [on Jan. 1] and being confused," he said at a University of Minnesota Forum.

While some people may be in the system in time, because of the compressed timeframe, there is a risk that some insurance cards may not be distributed on time.

"We want to make sure that we can get those cards into the hands of our members," Keefer said in an interview after the forum. "That's our brand; that's our promise to the state of Minnesota."

The problem has to do with an electronic file that includes vital information about each new enrollee. MNsure officials say they are sending that information to the insurance companies participating in the exchange. But insurance companies complain that some of the documents include errors, such as incorrect addresses.

At this point, MNsure and the insurance companies are cross-checking enrollment information to make sure everything squares. When it doesn't, insurance company representatives are manually entering personal information, something Keefer hopes keep to a minimum to avoid additional errors.

That could be a particular problem for people who choose to be billed later for their plan instead of paying up front on the MNsure site, insurance company officials say. If an insurer doesn't have accurate information about their new customers, the company won't send an invoice. Without a payment, they also won't issue a policy.

This week, MNsure sent people who have enrolled an email updating them on where they are in the process and what they can expect next, which Keefer said was a good development.

MNsure board chair Brian Beutner said consumers can expect more communication on the topic in coming weeks. He also said he is confident that people who have signed up for health insurance will have coverage on Jan. 1.

"If you as a consumer have been to the site, gone through the application process, made your payment, you will be assured that you will have coverage as of the day you selected," Beutner said.

State Commissioner of Human Services Lucinda Jesson, who also appeared at the forum, provided an update on a problem that surfaced last month. MNsure provided some people with inaccurate information about whether they were eligible for subsidies to pay for private insurance or for government health plans.

Jesson said even in October, the site's first month of operation, it was clear that some eligibility determinations weren't quite right. People should have been eligible for more than the system was reporting, she said.

MNsure officials have said the agency is double checking as many as 40,000 applications.

Jesson said she doesn't know how many people were affected, but probably most were not. She said insurance applicants will receive notices with their eligibility status soon.

MNsure officials recently told consumer assistors known as navigators that the online insurance marketplace is no longer accepting paper applications for coverage.

MNsure recently sent notices about the change to the navigators who help consumers enroll in government and commercial health either on the MNsure website or through paper applications.

Enrolling online is the best way to make sure coverage is available Jan. 1, said April Todd-Malmlov, MNsure's executive director. Consumers who don't have Internet access should use a navigator to help enroll on MNsure's website, she said.

"We have communicated out to our navigators that we would advise them that to ensure that those people have coverage that they should work with those individuals to submit their application online," Todd-Malmlov said.